Detecting hostname == localhost?

[Thiago Macieira]

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Michael Goffioul wrote:
>That's not what I meant. Imagine you're working on a computer named
>"myhost.mydomain.com" with the given IP "165.89.3.54", I want to check
>if strings like:
>
>myhost
>myhost.mydomain.com
>165.89.3.54
>
>corresponds to localhost, it means the computer you're working on.

I've just come up with an idea to make sure an address is node-local, that 
should work on any system. The idea is actually very simple: try to bind(2) 
to that address. If the kernel allows that binding, then it's a local 
address.

Sorry, I have no tested code as of now, but you could try something like this:

/* port 0 means any available port */
KExtendedSocket ks(hostname, 0, KExtendedSocket::passiveSocket);

// Use the next line if you don't want to do lookups
ks.setFlags(ks.socketFlags() | KExtendedSocket::noResolve);

if (ks.listen(1) == 0)
	// this is a local address
else
	// this is not a local address

ks.closeNow();

Note that, except for the lookup, all this is virtually non-blocking.

- -- 
  Thiago Macieira - UFOT Registry number: 1001
 thiagom at mail.com
   ICQ UIN: 1967141  PGP/GPG: 0x6EF45358
     Registered Linux user #65028
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